We tow a car. We find it necessary. We park the MH at a campground and do our sightseeing in the car. 30 mpg in the car is better than 9 mpg with the MH and a car is much easier to park at most attractions. Also easier to hookup than a dolly and car IMHO.
It depends on your camping style. We are travelers and sightseers. If you are campers that camp to enjoy the beach and campground, there may be no good reason to tow a car.
Friends of ours decided to buy a dolly to take their non towable car. They have since said they should have sold the car and get a towable car.